In part two, Professor Al-Khalili looks at the 19th century chemists who struggled to impose an order on the apparently random world of the elements. From working out how many there were to discovering their unique relationships with each other, the early scientists' bid to decode the hidden order of the elements was driven by false starts and bitter disputes. But ultimately the quest would lead to one of chemistry's most beautiful intellectual creations - the periodic table.

The third episode follows tigers, harpy eagles, chimpanzees, army ants and other predators as they rise to the challenge of hunting within the forest - a dense, confusing, three-dimensional world, one in which even finding prey is a maddening task. The prize for succeeding at nature's great game of hide-and-seek is one worth winning. Forests cover one third of the land surface, and concealed within are over half of the species on Earth.

On a vast plateau cradled in the heart of the rocky mountain range lies two million acres of unspoiled wilderness, never farmed and never fenced. Canyons, lakes, rivers and mountains, a refuge for magnificent animals and a spiritual sanctuary for generations of Americans, all resting on the largest super volcano in North America. This is Yellowstone, America's first national park, a raw and powerful beauty that truly comes to life through immersive 3D.

Meet Perseverance, NASA's latest rover, as it heads to Mars to answer one question: did life exist on the red planet? On the way, it will lay the foundation for human exploration of our closest neighbour.
Today, Mars is hostile to life. It's too cold for water to stay liquid on the surface, and the thin atmosphere lets through high levels of radiation, potentially sterilizing the upper part of the soil. But it wasn't always like this. Some 3.5 billion years ago or more, water was flowing on the surface. It carved channels still visible today and pooled in impact craters. A thicker carbon dioxide atmosphere would have blocked more of the harmful radiation. The Mars 2020/Perseverance rover is designed to better understand the geology of Mars and seek signs of ancient life. The mission will collect and store a set of rock and soil samples that could be returned to Earth in the future. It will also test new technology to benefit future robotic and human exploration of Mars, as the Ingenuity Helicopter.

Super quick computers and advanced mathematical formulas have taken over trading on the financial markets from human beings -algorithms- which seem to have a life of their own. The only ones who understand the system in any way are its architects, the algorithm developers. Haim Bodek is one such algo-developer. After finding some strange wrongdoings he set out on a personal crusade against this elusive system". The machinery behind our financial markets, consisting of mathematical models, data centers and miles and miles of fiber optic cables, is disguised by technological complexity and secrecy. The builders of this financial system are a new breed of Wall Street employees -quants- mathematicians and physicists who are responsible for a technological revolution. Haim Bodek is a quant; he specialized in artificial intelligence and worked for Goldman Sachs. He knows the system from the inside, he helped build it. Haim Bodek was invited to tell his story at the "Battle of the Quants" - a recurring event where quants discuss high-frequency trading, amongst other things. Bodek wrote an algorithm for trading machines that would generate guaranteed income - a money machine that weathered the financial meltdown of 2008. But then from one day to the next the algorithm stopped working.

Discover photographs, storyboards, conceptual art, publicity materials, archival documents, and behind-the-scenes footage of the original film and all its sequels that have never been shared before. Never Sleep Again expands on Wes Craven's behind creating the first Elm Street film.